This is mostly about the odds:

Obese people can expect to lose three years of life while the average overweight person will die 12 months sooner than they would have if they were a healthy size, researchers at Oxford, Cambridge and Harvard universities found.

Usually fewer than one in five men will die before the age of 70, but that jumps to nearly one in three for the moderately obese, and eight in 10 for the morbidly obese.

In contrast around one in 10 women can expect to die early, with obesity raising the risk to one in seven. While obesity raises the risk of early death by just three per cent for women, it is 10 per cent for men, more than three times as much.

Top Reddit comments:

I imagine this has something to do with the fact that men tend to develop more visceral fat as opposed to subcutaneous fat.

Visceral fat is stored within the abdominal cavity, and is thus closer to organs and can cause more problems than subcutaneous fat, which is outside the abdominal cavity just beneath the skin.

Visceral vs. subcutaneous fat also accounts for the "apple" shape that overweight men develop as opposed to the "pear" shape that women develop.

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To add on to this, visceral fat produces some disruptive substances that contribute to health issues and basically changes the way your body functions. It becomes really dangerous and interferes with normal hormonal functions and eventually makes it harder to lose weight. The visceral fat is the kind that sits around your organs and produces inflammatory substances, so it can cause a wide variety of health issues from heart problems to diabetes. 

Men really need to be made aware of how harmful visceral fat is, but menopausal women are also at risk of developing visceral fat as estrogen plays a key role in how fat is distributed throughout the body.

700+ Reddit comments:

https://reddit.com/r/science/comments/4sqas8/obesity_is_three_times_as_deadly_for_men_than/